1. Field of the Invention
The present invention relates to a medical ligature for ligating the tissue of a lesion inside a human body.
2. Description of the Related Art
In the past, there has been a medical ligature for ligating the tissue of a lesion in a human body trans-endoscopically, that is, by inserting the medical ligature into the human body through a therapeutic instrument insertion channel in an endoscope.
This kind of medical ligature is such that a wire made of a synthetic resin is looped to form a ligation loop on the distal side of the ligature, and the ligation loop is used to ligate the tissue of a lesion and indwelled intact in the human body for several days. As a result, a blood flow through the tissue of the lesion is arrested owing to the ligation. The tissue of the lesion therefore necroses several days later and drops. At this time, the medical ligature also drops and is excreted naturally through the anus.
In the foregoing known medical ligature, the ligation loop is used to ligate the tissue of a lesion, and a stopper is moved toward the distal end of the ligation loop in order to make the ligature loop smaller and thus ligate the tissue of the lesion with the ligation loop. At this time, since no member is provided for restricting the movement of the stopper, the ligation loop can assume any size during ligation and can be made unlimitedly small in terms of the structure. This means that adjusting the strength of ligation depends solely on the extent of an operator's force in practical use, and poses a problem that the efficacy of treatment varies depending on operator's expertise.